


Alone Together, For Worse or For Better

by etcspikes



Category: Haikyuu!!
Genre: Bickering, Brotherly Love, Gen, One Shot, Sibling Bonding, Sibling Rivalry, Sick Miya Atsumu, Sick Miya Osamu, Sickfic, haikyuu sickfic
Language: English
Status: Completed
Published: 2021-03-18
Updated: 2021-03-18
Packaged: 2021-03-27 05:53:55
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,233
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/30118134
Author URL: https://archiveofourown.org/users/etcspikes/pseuds/etcspikes
Summary: When Atsumu and Osamu both come down with a bad case of the flu, they're stuck at home with no one but each other for the weekend. With their parents out of town and the rest of their team busy with an all-day practice, it's only a matter of time before these sick twins destroy each other or otherwise learn to get along for a day.
Relationships: Miya Atsumu & Miya Osamu
Kudos: 79





	Alone Together, For Worse or For Better

**Author's Note:**

> i also posted this story on my wattpad account with the same user @etcspikes

It was a Saturday morning. The moment Osamu opened his eyes was the moment he regretted ever waking up, so groggy and so sick. With the way he had felt the day before, he knew that this day was only going to be worse- that's what happened every time. What bothered him more than this, though, was that his parents had entrusted Atsumu to take care of him. _Atsumu_ of all people. Of course, there really were no other options in their situation, but Osamu knew that even if his brother cared enough to help, he wouldn't be very good at it anyway.

Slowly sitting up, Osamu realized that his shirt clung to his chest from the amount of sweat he had produced while sleeping. It was a disgusting feeling, more so than all the fluid in his sinuses and the aching in his limbs, so he decided he would take a shower and change into clean pajamas before going back to bed. At that moment, it didn't matter what time it was or what Atsumu might think of him for sleeping in so late.

In the shower, Osamu had to admit he was frustrated that it didn't help anything. The warm water did nothing to ease the soreness in his muscles, rather, it only provoked sporadic waves of hot flashes and chills over his body instead. Because of this fluctuation, he concluded that he must have developed a fever; he could hardly stand without his legs giving out. Allowing the water to stream down his face, Osamu closed his eyes for a brief moment just to ease some of the pressure in his sinuses.

He was startled and opened his eyes again at the sound of the bathroom door handle being shaken. Even though he knew he had locked the door, he still froze at the idea that Atsumu would find a way to barge in. Instead, however, Atsumu just gave up and chose to knock instead.

"I'm taking a shower," Osamu responded, surprised at how much worse his voice sounded in comparison to the previous day. Over the flowing water, he heard one final pound on the door, followed by the sound of his brother's retreating footsteps. Once it was evident that Atsumu was gone, Osamu relaxed again and finished his shower.

When Osamu returned to their shared bedroom, he stopped in his tracks at the sight of Atsumu sleeping on the lower bunk of their bed. In addition to that, Atsumu was drooling on Osamu's pillow, as if to coincidentally spite him for ever getting up in the first place.

"Tsumu, get off. That's my bed," Osamu sat down on the floor and shook his twin by the shoulder. If this was going to result in another argument, he knew he didn't have the energy to fight back.

"Don't wanna," Atsumu slurred in a significantly hoarse voice and buried his face into Osamu's pillow, as if he was genuinely too tired to move. He sniffled twice in an attempt to clear the thick congestion in his nose but to no avail.

More concerned about trying to get his bed back than about Atsumu's health, Osamu reminded, "My germs are all over that pillow, you know. Weren't you trying to avoid getting sick?"

"Ugh, can't you see I already have your germs? Thanks to you, I was up most of the night because I couldn't _breathe_. I still can't."

"You can't just blame me for that. It's your immune system's fault for-"

"Just shut up and go get me some water. Go."

Unbelievable. The fact that Atsumu disregarded Osamu's needs for the benefit of his own once again was infuriating. Osamu concluded that if he actually had the strength to get a glass of water for _either_ of them, he would have gladly dumped it on Atsumu's face instead. Such was not the case, however, and he decided to close his eyes and let himself go limp against the bed frame instead. Only a brief moment of silence went by until Osamu heard from his brother again, "Samu, I wanted water. I'm serious, like, my throat actually hurts."

"I'm not your slave! If I can't get it for myself, I am _not_ getting it for you," Osamu snapped and glared at him. His suddenly angry tone only worsened the irritation in his throat and chest, causing him to break into a bout of coughing as a result.

"Is this because you want your bed back? Sorry, I hope you don't mind if I borrow it for a day."

"Why did you even get up from your own bunk in the first place?"

"Wanted pain medicine, you locked yourself in the bathroom, I don't wanna climb back up. Now I'm gonna sleep here, thanks."

"I can't believe you," Osamu grumbled as Atsumu fell asleep again. Since he was no longer awake, Osamu slowly rose to his feet and grabbed Atsumu's pillow and blanket from the top bunk. It wasn't entirely uncommon for them to exchange simple belongings like this; they had been doing it since infancy.

From there, Osamu decided to sleep on the couch. Though it was slightly crammed and he preferred the comfort of his own bed, he was able to fall asleep very quickly because of his never-ending exhaustion.

___ ___ ___

When Atsumu opened his eyes again two hours later, he was confused for a brief second as to why he was in Osamu's bed instead of his own above. Then it dawned on him that he had essentially taken it away from him. Smirking to himself in satisfaction, he pulled Osamu's blanket over his shoulders and turned onto his side. In doing so, however, a sharp pain stabbed at his head and rendered him uncomfortable where he lay. In addition to this, the congestion that plagued him had only worsened since the last time he was awake, which he didn't even think was possible, and he found himself entirely unable to breathe from his nose.

"Samu, bring me the pain medicine and some tissues," he groaned. As if on cue, he sneezed several times.

When Atsumu got a response of silence, he stuck his foot over the side of the bed to lightly kick Osamu, but he soon realized that his brother was not on the floor where he once had been. Sighing inwardly to himself, Atsumu sat up and looked around, seeing that Osamu was not even in the room anymore.

Forcing his heavy limbs out of bed against their will, Atsumu staggered to his feet. The act of standing up sent a wave of dizziness through his body, but he ignored it the best he could and trudged out of the bedroom to see Osamu curled up on the couch. He also noticed that his brother had taken both the box of tissues and the pain medicine at some point, seeing that both objects were placed on the coffee table in front of him.

With pure annoyance, Atsumu knelt down, poked his twin's cheek, and scoffed, "Hey, sleepyhead. Stop hogging this stuff, will ya? You're pretty useless, you know."

At once, Osamu opened his eyes and threw Atsumu's pillow at him. "No shit. Do I _look_ like I can do anything for you?"

"Well, it's not like I'd do anything for you either!" Atsumu threw the pillow back. Before Osamu could retaliate again, he snatched up the box of tissues and held it protectively against his chest. Aside from provoking his brother, that was the only thing he truly wanted.

Osamu sat up and got on his feet with Atsumu's blanket still around his shoulders. Although he swayed ever so slightly, he took a step forward and moved past Atsumu to the kitchen, where he rummaged around for something in one of the cabinets. Atsumu saw this as an opportunity to sit down on the couch and make himself comfortable, just as Osamu had done earlier. He also used several tissues and chose simply to cast them aside, rather than getting up again to throw them away.

"You know, I'm starting to think you don't care about how much I'm suffering, " Atsumu complained when Osamu returned carrying a box of fever-reducing patches and cough syrup. With an eye roll, Osamu placed the materials on the coffee table and chose to sit back down on the couch in the small area where Atsumu's used tissues were _not_ scattered. Since Atsumu no longer had the whole couch to himself, he pressed his foot into Osamu's shoulder and asked in repulsion,"Why are you sitting beside me like this?"

"So, I'm not allowed to rest anywhere, is that it?" Osamu's tone changed into one of complete irritability.

"Just go back to your bed. The couch is warmer, so _I'm_ taking it now!"

"No, you're not. If you make me get up again, I'll collapse before I get there!"

"Good! The floor isn't _that_ bad of a place to sleep!"

"If you like it so much, why don't you go try it out yourself? You must be _dying_ to know what hardwood tastes like!" Osamu moved closer and grunted with the effort of pushing Atsumu off of the couch. However, this action resulted in Atsumu grabbing him by the shoulders as he fell, which sent them both crashing to the floor in a tangle of limbs. From there, they got into a scuffle despite their weakened conditions.

Atsumu pushed Osamu's head against the floor and shouted, "Why don't you try it first, huh?!"

"That's your job! First born means you're first to lose!" Osamu grabbed his arm with both his hands and pulled it away from his head. Then he "punched" Atsumu across the jaw with a soft jab, realizing that he could not put any more of his diminished strength into the movement. It hadn't even hurt Atsumu to any degree. Neither of the twins showed any sign of relent, even if it was so visibly obvious that they were too weak to continue for long.

Atsumu struck his knee into Osamu’s abdomen, just below his ribcage, which forced the younger twin to break away in a violent coughing fit. Rather than showing any compassion for him, however, Atsumu cleared his throat and argued in a rougher voice than before, "Here you are coughing and wheezing and spewing your germs _everywhere_ \- it's disgusting! No wonder I got sick from you so easily!"

Once he could breathe again, Osamu shot back with more fatigue than before, "At least _I'm_ not leaving dirty tissues all over the place. You're the only disgusting one here, Tsumu."

"And whose fault is that?! You made me sick! You don't listen to my requests, you just go off and sleep the day away like the useless trash you are!"

"Again, that's because I'm sick, too. Why can't you be nice to me for one day?"

"I don't see _you_ being very kind either-"Atsumu's voice cracked and left him with a burning pain, allowing him to realize that his ability to project his voice was lessening for every added word he spoke. Perhaps this strain on his already sore throat was going to have negative consequences, but he wanted so badly to overlook this and find some way to win the fight against his brother, even if it meant he would lose his voice from it.

"You say that like you're not picking fights with me," Osamu yawned. Instead of defending himself, he pulled away and hoisted himself back onto the couch. "It's starting to get old, asshole."

Atsumu grabbed Osamu by the shirt with one hand and raised his other to hit him. With the little remaining voice he had left, he demanded, "What did you just call me?!"

Osamu turned his head away from Atsumu and closed his eyes, bracing for impact. He was practically a deadweight in Atsumu's grasp. When Atsumu actually hit him, however, he held back and did so with nowhere near the amount of force he originally wanted to. Was it out of sympathy? No, Atsumu told himself. There was no possible way he would show even a trace of that for Osamu, not with how much they were fighting and bickering. Why should he have any sympathy in the first place, when he felt just as bad as Osamu looked?

Even still, Atsumu hesitated to remove his hand from his brother's face after the hit. It felt warm, too warm, and perhaps there was even a brief moment that Atsumu had actually _regretted_ his decision. Osamu was burning up. With the combination of their sickness and their strong, violent emotions toward the other, it only made sense for his fever to have risen in that short amount of time.

"Hey, Samu, talk to me," Atsumu furrowed his brow, looking for some type of answer, even if he was unsure what kind of response he wanted.

Osamu leaned his head against the back of the couch and mumbled in between sniffles, "Stop making it so difficult for me, dammit."

"I'm the one making things difficult? That's funny because last I checked, _you_ were the one who got _both_ of us sick," Atsumu accused before he pulled another tissue from the box and sneezed into it. When he got nothing but a reply of silence from Osamu, he taunted, "Ha, you're trying to think up some kind of comeback, aren't you?"

Atsumu held the tissue to his nose as he waited again for Osamu to respond with some type of retort. Seeing that his brother was more asleep than not and therefore made no attempt to continue the bickering, he asked jokingly, "Samu, did you die over there?"

What he had not expected, however, was that Osamu reached such a state of sleep that he sat entirely limp, to the extent where his head began to drift toward Atsumu's shoulder. At this, Atsumu tried pushing him away and said, "No. Go put your head over there."

As soon as Atsumu put a hand on him to move him, however, Osamu's face contorted with pain and he softly groaned in protest. It was impossible to tell if he was fully conscious or not, but his discomfort over the slightest touch was enough for Atsumu to sense that something was wrong.

"Can you wake up for a sec? Just give me a sentence or something so I know you're okay. There's nothing funny about pretending to be unresponsive like this," Atsumu stated flatly and looked over Osamu's condition. Of course his face was flushed, as both of theirs were, but he seemed slightly more... _fragile_. Something about the way he gave in to the weakness and relied entirely on Atsumu for support, likely without even realizing, raised a great amount of concern.

"Shit," Atsumu muttered to himself as he dialed Kita's number and waited for him to pick up, not knowing what else he was supposed to do. It was so clear that Osamu wasn't _pretending_ to be unresponsive- he actually was. Atsumu hoped with all the willpower he had left that Kita wasn't too busy with practice to respond. In the meantime, he picked up a magazine from the coffee table and started to fan Osamu with it. Doing this only increased the weak, jelly-like feeling in his arms, but he tried to overlook this the best that he could in an attempt to cool his brother down.

" _Hey, is everything okay?_ " Kita's voice finally sounded from the other end of the phone after a few minutes' worth of missed calls.

"I need your help."

" _Now you're sick, too? I can hear it in your voice._ "

"That's not important right now. Tell me what I need to do to reduce Samu's fever."

" _Okay, how high is it_?"

"Um, I don't know," Atsumu turned his head to look at Osamu, who was drifting in and out of consciousness from his shoulder. Then he asked, "Samu, how high is your fever?"

"No...idea," Osamu replied lethargically and buried his face into his brother's neck. This was bad. He had to be seriously delirious to be displaying this much physical contact when the two of them always preferred not to.

Atsumu could hear Kita sigh from the other end, " _You can't just_ ask _him. You have to take his temperature._ "

"Oh, right. Let me find the thermometer."

" _Uh, I actually have to go- the coaches are calling me to the court_ ," Kita warned as Atsumu shakily stood to retrieve the thermometer. While he offered it to Osamu and began to take his temperature, Kita informed hurriedly, " _If it's above 39 degrees, take him to get medical treatment. If it's lower, keep him hydrated, give him fever-reducing medicine, and just let him sleep. I have to hang up now._ "

"Wait! How do I get him medical treatment if it's higher? I can't stand for more than a few minutes either."

" _Get your parents to- oh. That's right, you guys are home alone._ "

"Yeah! What am I gonna-" Atsumu was interrupted with coughing. When he tried to speak again, however, he found that he couldn't manage more than a whisper. Then, the thermometer beeped to signify that it had read Osamu's temperature. Atsumu took it from his mouth to look at it and sighed in relief when he saw that it was low enough that he could treat it at home, even if he himself was beyond exhausted. In a barely audible voice, Atsumu reassured, "I think he'll be okay."

" _Hey, your voice. Stop talking and I'll just drop some stuff off for you guys after this practice game ends. I have to go now. Bye._ "

The call ended, leaving Atsumu blank. Without Kita, he tried to remember the specific instructions he was given, considering that he too had a fever that put his mind in a fog. It certainly wasn't as bad as Osamu's just yet, provided that he was able to stay awake enough to realize that Osamu needed his help, but this didn't change the fact that the weakness in his sore body made it difficult to care for both of them.

Then, like some miracle, it dawned on him exactly what he needed to do again. Though he was much slower and had to take breaks for the sake of his own needs, he was able to keep Osamu awake long enough to give him medicine and water. Once they were settled again on the couch, Osamu unconsciously resorted to wrapping both of his arms around one of Atsumu's, which the older twin didn't fight this time. He concluded that that perhaps it would be best just to leave him be and instead just sighed, "You better expect payback for this when we get better, Samu."

The longer Atsumu sat with his brother curled up against him, the more tired he grew. It reminded him of when they were children and much more open to contact like this, the times that felt so far in the past where they would be sick or upset and turned to the other for comfort. As he thought back to those days, his eyes grew heavier and he decided to rest his own head on Osamu's. Unable to stay awake much longer, he relented and allowed himself to fall asleep with him. Perhaps it was okay to be nice to Osamu, just for one day.


End file.
